As an electrophotographic image forming apparatus such as a copy machine or printer, an apparatus having an electrophotographic process unit (hereinafter abbreviated as EPU) and a belt unit, each of which is attachable to and removable from the image forming apparatus body, is provided. The EPU integrally incorporates therein a process section that is necessary for forming a toner image on a photoconductive drum. The belt unit integrally incorporates therein a process section that is necessary for forming the toner image formed on the photoconductive drum by the EPU, onto a paper sheet.
In this manner, in the image forming apparatus having the EPU and the belt unit, conventionally, each unit is separately attached to and removed from the image forming apparatus body. Therefore, a slide rail for guiding the EPU and a slide rail for guiding the belt unit are arranged in the image forming apparatus body.
However, if a slide rail is arranged for each of the EPU and the belt unit, cost reduction may be obstructed by the expensive slide rails. Moreover, since space for installing the slide rails must be secured at two positions in the image forming apparatus body, miniaturization of the apparatus may be obstructed.
Thus, it is desired to develop a processing unit for an image forming apparatus that realizes lower price and miniaturization of the image forming apparatus and that enables smooth attachment and removal of plural process units to and from the image forming apparatus body.